Various radio systems offer so-called song-tagging services. The basic principle of such services consists of storing an identification code (e.g., a 32-bit Apple ID) assigned to the audio content just played when a keystroke is executed. At a later point, such a stored identification code (e.g., the Apple ID) can be transmitted via a computer (such as an iPod/iPhone) to the PC and this song then be purchased or generally obtained from a remote data store (such as an iTunes store). To do so, in an implementation in HD radio, the identification code (the ID) is transmitted as component of the program service data and the station information service data and may then be extracted there. In an implementation in FM radio, an iTunes tagging ODA (open data application), for instance, is able to be transmitted via RadioText+, from which the Apple ID is extracted. In an implementation in XM radio, the identification code (e.g., the Apple ID) can be transmitted via a song tagging data service (for instance according to the XM spec: SX-9845-0043_Song_Tagging_XM_Band.pdf). The assignment of the identification code (Apple ID) to the audio program content is made via a PID (program identification, which represents a unique 4-byte time stamp, which is assigned to each song transmitted during the day), the PID being transmitted with the audio program and also via a data service as part of a so-called tag label group. The song tagging data service transmits tag label groups for all channels of the XM channel lineup. Said XM specification describes the assignment process as the localization of tag label groups for an SID-of-interest (SID being an identifier of an audio channel). Because of the time offset between the audio program and the label group transmission, two label groups are to be buffer-stored for these SIDs, and the PIDs compared to the PID of the selected audio channel. If a match is found, the Apple ID and associated song metadata are to be persistently stored for a later transmission to the iPod in the device.